#include <stdio.h>

int main(int argc, const char *argv[])
{
	int i = 0;
	int j = 0;
	int h = 0;
	char value = 'F';
	while(i < 6)
	{
		j = 0;
		while(j < i)
		{
			printf("_");
			j++;
		}
		value = 'F';
		
		h = 0;
		while(h <= i)
		{
			printf("%c", value);
			value--;
			h++;
		}

		putchar(10);
		i++;
	}

	return 0;
}
